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Diffstat (limited to 'src/Crypto/jitterentropy.h')
| -rw-r--r-- | src/Crypto/jitterentropy.h | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/src/Crypto/jitterentropy.h b/src/Crypto/jitterentropy.h new file mode 100644 index 00000000..b6929933 --- /dev/null +++ b/src/Crypto/jitterentropy.h @@ -0,0 +1,155 @@ +/* + * Non-physical true random number generator based on timing jitter. + * + * Copyright Stephan Mueller <smueller@chronox.de>, 2014 + * + * License + * ======= + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, and the entire permission notice in its entirety, + * including the disclaimer of warranties. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote + * products derived from this software without specific prior + * written permission. + * + * ALTERNATIVELY, this product may be distributed under the terms of + * the GNU General Public License, in which case the provisions of the GPL are + * required INSTEAD OF the above restrictions. (This clause is + * necessary due to a potential bad interaction between the GPL and + * the restrictions contained in a BSD-style copyright.) + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF + * WHICH ARE HEREBY DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE + * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + */ + +/* Adapted for VeraCrypt */ + +#ifndef _JITTERENTROPY_H +#define _JITTERENTROPY_H + +#include "jitterentropy-base-user.h" + +/* The entropy pool */ +struct rand_data +{ + /* all data values that are vital to maintain the security + * of the RNG are marked as SENSITIVE. A user must not + * access that information while the RNG executes its loops to + * calculate the next random value. */ + uint64_t data; /* SENSITIVE Actual random number */ + uint64_t old_data; /* SENSITIVE Previous random number */ + uint64_t prev_time; /* SENSITIVE Previous time stamp */ +#define DATA_SIZE_BITS ((sizeof(uint64_t)) * 8) + uint64_t last_delta; /* SENSITIVE stuck test */ + int64_t last_delta2; /* SENSITIVE stuck test */ + unsigned int osr; /* Oversample rate */ + int fips_enabled; /* FIPS enabled? */ + unsigned int stir:1; /* Post-processing stirring */ + unsigned int disable_unbias:1; /* Deactivate Von-Neuman unbias */ +#define JENT_MEMORY_BLOCKS 64 +#define JENT_MEMORY_BLOCKSIZE 32 +#define JENT_MEMORY_ACCESSLOOPS 128 +#define JENT_MEMORY_SIZE (JENT_MEMORY_BLOCKS*JENT_MEMORY_BLOCKSIZE) + unsigned char *mem; /* Memory access location with size of + * memblocks * memblocksize */ + unsigned int memlocation; /* Pointer to byte in *mem */ + unsigned int memblocks; /* Number of memory blocks in *mem */ + unsigned int memblocksize; /* Size of one memory block in bytes */ + unsigned int memaccessloops; /* Number of memory accesses per random + * bit generation */ +}; + +/* Flags that can be used to initialize the RNG */ +#define JENT_DISABLE_STIR (1<<0) /* Disable stirring the entropy pool */ +#define JENT_DISABLE_UNBIAS (1<<1) /* Disable the Von-Neuman Unbiaser */ +#define JENT_DISABLE_MEMORY_ACCESS (1<<2) /* Disable memory access for more + entropy, saves MEMORY_SIZE RAM for + entropy collector */ + +/* -- BEGIN Main interface functions -- */ + +#ifndef JENT_STUCK_INIT_THRES +/* + * Per default, not more than 90% of all measurements during initialization + * are allowed to be stuck. + * + * It is allowed to change this value as required for the intended environment. + */ +#define JENT_STUCK_INIT_THRES(x) (x/10 * 9) +#endif + +#ifdef JENT_PRIVATE_COMPILE +# define JENT_PRIVATE_STATIC static +#else /* JENT_PRIVATE_COMPILE */ +# define JENT_PRIVATE_STATIC +#endif + +#ifdef __cplusplus +extern "C" { +#endif + +/* Number of low bits of the time value that we want to consider */ +/* get raw entropy */ +JENT_PRIVATE_STATIC +ssize_t jent_read_entropy(struct rand_data *ec, char *data, size_t len); +/* initialize an instance of the entropy collector */ +JENT_PRIVATE_STATIC +struct rand_data *jent_entropy_collector_alloc(unsigned int osr, + unsigned int flags); +/* clearing of entropy collector */ +JENT_PRIVATE_STATIC +void jent_entropy_collector_free(struct rand_data *entropy_collector); + +/* initialization of entropy collector */ +JENT_PRIVATE_STATIC +int jent_entropy_init(void); + +/* return version number of core library */ +JENT_PRIVATE_STATIC +unsigned int jent_version(void); + +/* -- END of Main interface functions -- */ + +/* -- BEGIN error codes for init function -- */ +#define ENOTIME 1 /* Timer service not available */ +#define ECOARSETIME 2 /* Timer too coarse for RNG */ +#define ENOMONOTONIC 3 /* Timer is not monotonic increasing */ +#define EMINVARIATION 4 /* Timer variations too small for RNG */ +#define EVARVAR 5 /* Timer does not produce variations of variations + (2nd derivation of time is zero) */ +#define EMINVARVAR 6 /* Timer variations of variations is too small */ +#define EPROGERR 7 /* Programming error */ +#define ESTUCK 8 /* Too many stuck results during init. */ + +/* -- BEGIN statistical test functions only complied with CONFIG_CRYPTO_CPU_JITTERENTROPY_STAT -- */ + +#ifdef CONFIG_CRYPTO_CPU_JITTERENTROPY_STAT +JENT_PRIVATE_STATIC +uint64_t jent_lfsr_var_stat(struct rand_data *ec, unsigned int min); +#endif /* CONFIG_CRYPTO_CPU_JITTERENTROPY_STAT */ + +/* -- END of statistical test function -- */ + +#ifdef __cplusplus +} +#endif + + +#endif /* _JITTERENTROPY_H */ |